Web Real-Time Communication (WebRTC) is a technology that provides voice calls, video chat, Video Telephone (VT or Video Call), video conferencing, and file transfer through browser applications without additional plug-in installation.
An IP Multimedia Subsystem or an IP Multimedia core network Subsystem (IMS) is a technology that is the base of Voice over Long-Term Evolution (VoLTE) and Rich Communication Services (RCS) and provides functions, such as voice all, video call, video chat, video conferencing, Short Message Service (SMS) over IMS, conference call, Instance Message (IM), group chat, file transfer, image/video share, presence and the like.